test: migrate stats/base/dists/rayleigh/logcdf to ULP-based assertions - #14322

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/base/dists/rayleigh/logcdf from EPS-scaled relative tolerance comparisons to ULP-based assertions using @stdlib/assert/is-almost-same-value, per [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352.

Changes are limited to test files:

• test/test.logcdf.js
• test/test.factory.js
• test/test.native.js

In each fixture loop, the if ( y === expected[i] ) { ... } else { delta/tol ... } branch was replaced with

t.strictEqual( isAlmostSameValue( y, expected[ i ], 0 ), true, 'returns expected value' );

and the now unused @stdlib/math/base/special/abs and @stdlib/constants/float64/eps requires (along with the delta and tol locals) were removed.

Final ULP constant: 0 (all fixture loops, in both the JavaScript and native test files).

The bound was tightened agentically: starting from a high value and lowering it to the minimum integer that still passes. The measured minimum is 0 for every fixture file — the JavaScript implementation, the factory-generated function, and the native implementation each reproduce the Julia reference values bit-exactly across all 3000 fixture values (1000 each in small_scale.json, medium_scale.json, and large_scale.json).

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

Questions

Any questions for reviewers of this pull request?

The measured minimum is 0 ULP, which is what is committed here. If reviewers would prefer a small amount of headroom (e.g., 1) to guard against platform-specific differences on architectures not exercised locally, that is an easy change.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

Verification performed locally on linux/x64, Node.js v22:

• test/test.js — 3 passing
• test/test.logcdf.js — 3011 passing
• test/test.factory.js — 3013 passing
• test/test.native.js — 3011 passing (the native add-on was compiled locally via node-gyp rebuild, so these assertions actually executed rather than being skipped)

The full suite was run twice at the final ULP value with identical results, confirming no FMA/arch-dependent flakiness locally. make lint-javascript-tests TESTS_FILTER=".*/stats/base/dists/rayleigh/logcdf/.*" passes cleanly, and the only files changed are the three test files.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

This PR was written primarily by Claude Code, which mirrored the conversion idiom from already-migrated packages (e.g., stats/base/dists/rayleigh/pdf and stats/base/dists/arcsine/logcdf) and empirically determined the minimum ULP bound over the full fixture set.

@stdlib-js/reviewers

Generated by Claude Code